Drug metabolism can be altered by biological response modifiers such as hyperthermia. Cyclophosphamide activation to alkylating species is decreased under hyperthermia both in vivo in human and in vitro with rat liver preparations. The cellular pharmacology of the amino sustituted anthracycline analogs N,N dimethyl adriamycin and N,N dimethyl daunorubicin show greater cellular uptake than for adriamycin and daunorubicin but shows similar effects on DNA and RNA synthesis. These analogs are significantly metabolized in vivo in rabbits. Adriamycin actinoylhydrazone is metabolized in vivo in rabbits yielding high drug concentrations in the lung.